An LED (LIGHT EMITTING DIODE) is a semiconductor light emitting device for converting current to light.
A wavelength of light emitted by the LED depends on semiconductor materials used for manufacturing the LED. This is because the wavelength of emitted light varies depending on a band gap of the semiconductor materials, which represents difference in energy between valence band electrons and conduction band electrons.
Recently, the brightness of LED has been increased so that the LED is used as a light source for a display apparatus, an illumination device, and a light source for a vehicle. In addition, the LED can emit white light having superior efficiency by using fluorescent material or by combining LEDs having various colors.